heat your cast iron pan over medium-high heat, and drizzle in olive oil. once the pan is hot, add in the brussel sprouts and cook for about 2 minutes. add in the red onion, green and orange peppers, and garlic. season to taste with salt and pepper. continue to cook until the veggies are slightly charred. once cooked, remove from the cast iron from the heat. toss the chopped cilantro and lemon juice into the vegetable mix (optional). serve warm. enjoy!